[JarryShaw]

• Searched for similar pull requests
• Followed the coding style (make pylint, make mypy, make isort) — run with the Makefile flags on the touched files: isort clean, mypy clean, pylint no new messages
• make test passes, and a test case covers the change — the modules listed below only, not the whole suite
• Added a changelog entry under docs/source/changelog/ and regenerated CHANGELOG.md, if the change is user-visible — N/A, added centrally

What is the purpose of your pull request?

• fix — corrects a defect

---

Description of your pull request and other information

Closes #1184. Path: from_data → __post_init__ → unpack → HIP.read → Internet._decode_next_layer (internet.py:236) → HIP.alias → self._info, which Protocol.__post_init__ assigns only after read returns. read now sets self._info = hip just before decoding the next layer. alias is unchanged, since test_hip_unit.py pins it as reading _info. Standalone HIP parse and make hit the same error, and are fixed too.

Probe over the 49 HIP headers in options-internet.pcap:

• HIP.from_data: 49 raise → 0 raise, 49/49 byte-exact
• IPv6.from_data, merged with fix(ipv6): keep the extension-header chain in from_data rebuilds (#1177) #1182's head 55c8ed67e in a scratch branch: 49 raise → 49/49 byte-exact

Tests: new tests/protocols/internet/test_hip_from_data_alias_unit.py. Without the fix, all 6 subtests fail with the _info AttributeError; with it, 3 passed, 6 subtests passed. These also pass: test_hip_unit (34), the 5 other test_hip_*_unit modules, test_internet_unit, test_option_roundtrip_unit, and tests/project (389 passed, 1 skipped). run_unittest_leg.py protocols/internet reports 475 tests with 0 failures.

[JarryShaw]

Cross-review verdict on 6ad13e101: GOOD TO GO (ran on Sonnet; author Opus). Labelled review: good-to-go.

• Root cause: _decode_next_layer reads self.alias inside read, before __post_init__ assigns _info (protocol.py:1051). Setting _info early assigns the same dict object, and the extension=True path is untouched.
• Scope of the hazard: HIP's is the only alias that reads _info on a _decode_next_layer path, checked with a grep across pcapkit/protocols.
• Capture result: on options-internet.pcap, every HIP frame rebuilds byte-exactly through HIP.from_data, and through IPv6.from_data once merged with fix(ipv6): keep the extension-header chain in from_data rebuilds (#1177) #1182. That is 48 or 49 frames depending on the harness; the reviewer counted 46 HIPv2 + 2 HIPv1.
• Merge fix(ipv6): keep the extension-header chain in from_data rebuilds (#1177) #1182 together with this PR. I re-measured fix(ipv6): keep the extension-header chain in from_data rebuilds (#1177) #1182's head 55c8ed67e alone myself: all 49 HIP frames raise AttributeError in IPv6.from_data.
• Tests: without the fix, the new test fails 6 of 6 subtests. The protocols/internet leg runs 475 tests, 0F/0E.
• Out of scope: HIP.make(parameters=None) writes Header Length 0 against RFC 7401 §5.1's minimum of 4. Filed as fix(hip): make() without parameters writes Header Length 0, below the RFC 7401 minimum of 4 #1189.

[github-actions]

Coverage: 88.89% (unit tier, Python 3.14, 6ad13e101, Unit Tests run success)

Package	Statements	Missed	Branches	Partial	Cover
pcapkit (top level)	104	4	20	4	93.55%
pcapkit/const	18757	1034	2342	845	90.24%
pcapkit/corekit	1878	91	580	22	94.34%
pcapkit/dumpkit	142	0	42	0	100.00%
pcapkit/foundation	2442	102	852	39	94.38%
pcapkit/interface	112	7	40	5	92.11%
pcapkit/protocols	15708	188	3974	163	98.19%
pcapkit/toolkit	487	65	144	1	85.42%
pcapkit/utilities	429	4	122	4	98.55%
pcapkit/vendor	4409	2359	1006	158	42.84%

Per-file detail: the coverage-html artifact of this run.